The invention relates to a hybrid gas generator for an air bag.
From EP 0 616 578 B1 a hybrid gas generator of the generic type with a storage chamber for gas is known, with the storage chamber being sealed by a first bursting disk. An ignitable, gas-generating solid fuel charge is arranged in a combustion chamber. A separating wall, which limits the combustion chamber and which can be torn away, is connected to a hollow sliding piston for piercing the first bursting disk. A second bursting disk is arranged in the separating wall between the combustion chamber and the cavity of the sliding piston. Upon the ignition of the gas-generating solid fuel charge, the separating wall with the sliding piston tears away from the combustion chamber as a result of the pressure which builds up, and the point of the sliding piston punctures the first bursting disk to the storage chamber. Thereupon, cold gas can reach a gas bag by way of exit openings. The second bursting disk in the separating wall bursts under the pressure which continues to build up in the combustion chamber, and hot gas flows into the storage chamber and heats the stored gas there.
A disadvantage of this is the very costly construction which makes economical manufacture difficult.